1. Technical Field
The present invention relates to an image display device and a technology of displaying a plurality of images.
2. Related Art
Recently, an image display apparatus (a stereoscopic image display apparatus) for allowing an observer to observe a stereoscopic image by the naked eyes has been developed. For example, in a twin-lens stereoscopic image display device, two parallax images are displayed and are guided in two directions. An angle between the two directions is relatively small. The observer observes a first parallax image by the right eye and observes a second parallax image by the left eye, thereby observing the stereoscopic image.
The stereoscopic image display apparatus generally includes a liquid crystal panel and a barrier plate or a lens plate. The barrier plate is a light-shielding plate in which a plurality of openings is formed. The lens plate includes a plurality of cylindrical lenses.
Recently, an image display apparatus (a two-dimensional image display apparatus) for allowing an observer to observe an image (a two-dimensional image) which varies according to the position thereof has been developed. For example, in a two-dimensional image display device for two screens, two images are displayed and are guided in two directions. An angle between the two directions is relatively large. An observer who is positioned in a first region can observe a first image and an observer who is positioned in a second region can observe a second image.
The two-dimensional image display apparatus generally includes a liquid crystal panel and a barrier plate (JP-A-2005-172925).
If the barrier plate is used, since a portion of light is blocked by the barrier plate, the brightness of the image is reduced compared with a case where the lens plate is used. Accordingly, the lens plate is preferably used.
However, in the known two-dimensional image display apparatus, the lens plate was used. This is because, if the lens plate is used, it is difficult to increase the angle between the two directions in which the two images are guided, compared with the case where the barrier plate is used. This problem occurs even in the stereoscopic image display device.